Water-based, water-fast ink compositions containing a binder matrix of a monomeric polyacid and a monomeric polybase

ABSTRACT

Water-based, water-fast ink compositions are provided. The compositions contain an aqueous liquid vehicle, a colorant, e.g., a pigment, dye or stain, and a binder material capable of ionically or physically entrapping the selected colorant. The binder material contains two ionically associated components which form a matrix, and comprises either a combination of a monomeric polyacid and a monomeric polybase, or a combination of a basic polymer and an organic acid.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a divisional of U.S. patent application Ser. No.08/733,891, filed Oct. 18, 1996 U.S. Pat. No. 5,885,338, which was acontinuation-in-part of U.S. patent application Ser. No. 08/420,847,filed Apr. 11, 1995 U.S. Pat. No. 5,973,025, which was acontinuation-in-part of U.S. patent application Ser. No. 08/225,993,filed Apr. 12, 1994, now abandoned.

TECHNICAL FIELD

The present invention relates generally to ink compositions, and moreparticularly relates to novel water-based, water-fast ink compositions,and to binder materials useful therein.

BACKGROUND

Concern for the environment as well as increasingly stringent regulationof air quality, pollution and hazardous waste has created a need foralternatives to the use of petroleum and petroleum-based products in inkcompositions. The primary focus has been on the development of water-and soy-based printing inks. The major reason for using water-based inkcompositions is that because organic solvents are not present except invery small quantities, potential problems such as toxicity, flammabilityand other hazards are minimized.

Traditional water-based inks are based on resin systems which aredispersed in water. Several references describe inks which are based onaqueous vehicles. U.S. Pat. No. 5,106,417 to Hauser et al., for example,describes low viscosity aqueous printing ink compositions based onpolyacrylic resins containing carboxyl groups, and which also contain ahumectant, pigment and, optionally, a water-dilutable organic solvent.U.S. Pat. No. 5,166,245 to Zuraw et al. describes water-based printinginks made with modified rosin grinding resins. U.S. Pat. No. 5,242,489to Schwarz, Jr., et al., describes an ink composition containing apolymeric additive in addition to a colorant and an aqueous liquidvehicle. U.S. Pat. No. 5,244,496 to Easton et al. describes a water-fastink composition containing an amine, an acrylic emulsion resin binder, atriamine dye, and water.

The major drawback of the currently available water-based inks, however,is their generally poor water fastness, which limits their utility.

The present invention is addressed to the aforementioned limitation inthe art, and provides a water-based ink composition which is alsowater-fast. That is, the ink compositions are prepared in water, butafter printing and drying become insoluble in water and, depending onthe formulation, are also insoluble in alkaline solutions, detergents,and common organic solvents such as alcohols, acetone and toluene.

The novel ink compositions are advantageous in other ways as well. Incontrast to many ink compositions of the prior art, the compositions ofthe invention may be used on a wide variety of substrates, dry quicklyafter application, and tend not to bleed, smear or rub after drying. Thebinder materials and colorant are selected so that the colorant isentrapped by the binder matrix, substantially eliminating thepossibility that the colorant will leach. In addition, the present inkcompositions are generally low in viscosity (and thus relatively easy towork with), display good soak resistance, are generally stable atelevated temperatures, and have a relatively long shelf life, typicallyon the order of a year or more. It must also be emphasized that the inkcompositions may be readily tailored with respect to (1) viscosity,surface tension, dielectric constant and color density by varying theamount or type of components used, and (2) end use, i.e., as continuousjet printing inks, drop-on-demand inks, or the like.

SUMMARY OF THE INVENTION

It is accordingly a primary object of the invention to address theabove-mentioned need in the art by providing a water-based inkcomposition which is also water-fast.

It is another object of the invention to provide such a compositionusing a novel binder material that serves to entrap the selectedcolorant.

It is still another object of the invention to provide such acomposition wherein the binder material comprises a matrix of twoionically associated components which in combination serve to entrap theselected colorant.

It is a further object of the invention to provide such a compositionwherein the binder material comprises a matrix of a monomeric polyacidand a monomeric polybase.

It is still a further object of the invention to provide such acomposition wherein the binder matrix comprises a combination of a basicpolymer and an organic acid, preferably a monomeric polyacid.

It is yet a further object of the invention to provide such acomposition in the form of a jet printing ink.

It is another object of the invention to provide such a composition toprovide "drop-on-demand" printing, for example in conjunction withpersonal computer-associated printers (i.e., "pc printing"compositions).

Additional objects, advantages and novel features of the invention willbe set forth in part in the description which follows, and in part willbecome apparent to those skilled in the art upon examination of thefollowing, or may be learned by practice of the invention.

In a first embodiment, the invention relates to a novel ink compositionuseful in a variety of printing contexts, e.g., it may be used as a jetprinting, pc printing, flexographic, lithographic or screen printingink. The ink formulation is prepared in water, but is insoluble in waterafter drying on a substrate.

The binder material of the ink formulation is a novel matrix whichcomprises a combination of ionically associated components whichinteract to bind the selected colorant. More specifically, the bindermaterial is a combination of a monomeric polyacid and a monomericpolybase, or a combination of a basic polymer and an organic acidcomponent which may be a monoacid or a polyacid, and may be monomeric orpolymeric, but is preferably a monomeric polyacid. The colorant may be apigment, stain or dye, but in the preferred embodiment herein is a dyehaving acidic or basic groups.

DETAILED DESCRIPTION OF THE INVENTION

Before the present compounds, compositions and methods are disclosed anddescribed, it is to be understood that the terminology used herein isfor the purpose of describing particular embodiments only and is notintended to be limiting.

It must be noted that, as used in the specification and the appendedclaims, the singular forms "a", "an" and "the" include plural referentsunless the context clearly dictates otherwise. Thus, for example,reference to "a polyacid" includes mixtures of two or more polyacids,reference to "a polybase" includes mixtures of two or more polybases,reference to "a colorant" includes mixtures of two or more colorants,reference to "a solvent" includes one or more solvents, and the like.Also, it should be noted that reference to "a mer unit" or "a monomerunit" having a particular generic structure includes reference to two ormore mer units which may or may not have the same specific structure.

In this specification and in the claims which follow, reference will bemade to a number of terms which shall be defined to have the followingmeanings:

The term "water-soluble" as used herein to describe the nature of theink composition prior to drying on a substrate is intended to mean thatthe composition dissolves virtually completely in water. Generally, thiswill mean that the solubility of the composition is at least about 0.5mg/ml in water.

The term "water-fast" as used herein to describe the nature of the inkcomposition after drying on a substrate is intended to mean that thedried composition is substantially insoluble in water, such that uponcontact with water, the dried ink retains at least about 90%, andpreferably at least about 95%, of optical density.

The term "biocompatible" to describe the preferred ink compositions ofthe invention is used to mean that the components of the compositions donot degrade or otherwise adversely affect biological materials in anysignificant way.

The term "organic solvent" is used herein in its conventional sense torefer to a liquid organic compound, typically a monomeric organicmaterial in the form of a liquid, preferably a relatively nonviscousliquid, the molecular structure of which contains hydrogen atoms, carbonatoms, and optionally other atoms as well, and which is capable ofdissolving solids, gases or liquids.

The term "entrap" is used herein to refer to the binding of the colorantby the binder matrix such that after the ink composition dries on asubstrate, leaching of colorant from the binder material does not occur.In general, the colorant is physically entrapped by the binder material,i.e., is physically retained by the binder matrix. In some cases, whenionizable or ionized species are present on the colorant, the colorantis ionically bound by the binder matrix as well.

The term "alkyl" as used herein refers to a linear, branched or cyclicsaturated hydrocarbon group of 1 to 24 carbon atoms, such as methyl,ethyl, n-propyl, isopropyl, n-butyl, isobutyl, t-butyl, octyl, decyl,tetradecyl, hexadecyl, eicosyl, tetracosyl and the like. Preferred alkylgroups herein contain 1 to 12 carbon atoms, and particularly preferredalkyl groups contain 1 to 8 carbon atoms. The term "lower alkyl" isintended to mean an alkyl group of one to six carbon atoms, preferablyone to four carbon atoms.

The term "alkenyl" as used herein refers to a linear, branched or cyclichydrocarbon group of 2 to 24 carbon atoms containing 1 to 8, typically 1to 3, double bonds, and includes, for example, ethylene, n-propylene,isopropylene, n-butylene, octylene, cylohexylene, and the like.Preferred alkenyl groups herein contain 2 to 12 carbon atoms, andparticularly preferred alkenyl groups contain 2 to 8 carbon atoms. Theterm "lower alkenyl" is intended to mean an alkenyl group of two to sixcarbon atoms, preferably two to four carbon atoms.

The term "alkoxy" as used herein refers to an alkyl group bound throughan oxygen atom, e.g., methoxy, ethoxy, or the like. The term "loweralkoxy" is intended to mean an alkoxy group of one to six carbon atoms,preferably one to four carbon atoms.

The term "alkylene" as used herein refers to a difunctional saturatedbranched or unbranched hydrocarbon chain containing from 1 to 24 carbonatoms, and includes, for example, methylene (--CH₂ --), ethylene (--CH₂--CH₂ --), propylene (--CH₂ --CH₂ --CH₂ --), 2-methylpropylene [--CH₂--CH(CH₃)--CH₂ --], hexylene [--(CH₂)₆ --], octylene [--(CH₂)₈ --] andthe like. "Lower alkylene" refers to an alkylene group of 1 to 6, morepreferably 1 to 4, carbon atoms.

The term "alkenylene" as used herein refers to a difunctional branchedor unbranched hydrocarbon chain containing from 2 to 24 carbon atoms,and 1 to 8, more typically, 1 to 3, double bonds, e.g., propenylene(--CH₂ --CH═CH--), hexenylene [--(CH₂)₄ --CH═CH--], octylene [--(CH₂)₄--CH═CH--(CH₂)₂ --] and the like. "Lower alkenylene" refers to analkenylene group of 2 to 6, more preferably 2 to 4, carbon atoms.

The term "aryl" is used to refer to a functional group containing one tothree aromatic rings. When the aryl group contains two or more aromaticrings, they may be fused, as in naphthalene, anthracene, phenanthrene,or linked, either directly, as in biphenyl, or through a bridge, e.g.,an alkylene linkage or a --(CO)-- bond, as in benzophenone. The arylgroups herein may or may not be substituted. If substituted there may beone to five substituents on a ring, depending on the structure;generally, an individual aromatic ring, if substituted, will contain oneto two substituents, which will typically be lower alkyl, lower alkoxyor hydroxyl substituents.

The prefix "poly-" as in "polyacid" or "polybase" is intended to meanthat the compound so designated has two or more acidic groups or two ormore basic groups, respectively. Thus, the term "polyacid" hereinencompasses a diacid, and the term "polybase" herein encompasses adibase.

The term "polymer" is used herein in its conventional sense to refer toa compound having two or more monomer units, and is intended to includehomopolymers as well as copolymers. The term "monomer" is used herein torefer to compounds which are not polymeric.

"Optional" or "optionally" means that the subsequently described eventor circumstance may or may not occur, and that the description includesinstances where said event or circumstance occurs and instances where itdoes not. For example, the phrase "optionally substituted lower alkylgroup" means that a lower alkyl group may or may not be substituted andthat the description includes both unsubstituted lower alkyl groups andlower alkyl groups where there is substitution.

The aqueous ink compositions of the invention accordingly comprise anaqueous liquid vehicle, an effective amount of a colorant, and a bindermaterial. The binder material comprises two components which areionically associated to form a matrix, which serves to entrap thecolorant as explained above.

In one embodiment, the first component of the binder matrix is apolyacid, and the second component is a polybase. Again, the onlylimitation on the particular species selected is that the combinationprovide for complete entrapment of colorant such that there is noleaching after the ink has been applied to and allowed to dry upon asubstrate. Generally, it is desirable that the polyacid and polybase bepresent in a ratio ranging from about 1:5 to 5:1 (wt/wt), preferablyfrom about 1:2 to 2:1 (wt/wt).

The polyacids in this embodiment are represented by structural formula(I) ##STR1## wherein w, x, y, z, L and R are defined as follows.

The substituent R is:

alkyl, including linear, branched and cyclic alkyl, e.g., methyl, ethyl,n-propyl, isopropyl, or the like, substituted with zero to nsubstituents such as hydroxyl, amino, or lower alkoxy, wherein n willdepend on the size of the alkyl group, i.e., on the number ofsubstitutable C--H bonds which are present (thus, linear alkyl groupscontaining 1 to 8 carbon atoms may be substituted with 2-16 nonhydrogensubstituents), but will typically not exceed 6;

alkenyl, including linear, branched and cyclic alkenyl, substituted withzero to n substituents as above, with n generally not exceeding 6;

aryl of 1 to 3 rings which may be fused or linked, and, if linked, thelinkage between the aromatic rings may be direct or through a loweralkylene chain, a lower alkenylene chain, or a --(CO)-- bond, and boththe aromatic rings and the lower alkylene chain, if one is present, maybe substituted with one or more hydroxyl groups, amino groups, loweralkyl groups, or combinations thereof, with generally up to 4substituents on each aromatic ring; or

a heterocyclic moiety containing 5 or 6 atoms in the ring and 1 to 3heteroatoms selected from the group consisting of N, S and O.

L is an optional linking moiety, and if present, will generally be analkylene or alkenylene chain of 1 to 12, preferably 1 to 8, mostpreferably 1 to 6, carbon atoms.

The subscripts are as follows: w is 0 or 1; x is 0 or 1; y is an integerwhich is at least 2, and preferably is in the range of 2 to 10; and z is1, 2 or 3. When w is 0, then x is 0 and y is necessarily 2 and thecompound is oxalic acid. When z is greater than 1, i.e., is 2 or 3, thecompound will contain 2 or 3 R groups, respectively, which are asdefined above but may be the same or different, and will be linked toone another through a covalent bond, or through an alkylene oralkenylene linkage such as "L", as defined above.

Within this group, preferred polyacids are wherein x is 0, w is 1, y is2-6, and z is 1--so that the polyacids having the structural formulaR(COOH)_(y) --and R is alkyl of 1 to 12 carbon atoms substituted with 0to 4 substituents, alkenyl of 2 to 12 carbon atoms substituted with 0 to4 substituents and containing 1 or 2 double bonds, wherein thesubstituents are amino, hydroxyl, or combinations thereof, or R is arylof 1 to 2 rings, and if 2 rings, the rings are optionally substituted asexplained above and are either fused or linked.

Particularly preferred polyacids within this group are wherein x is 0, wis 1, y is 2, 3 or 4, and z is 1, and R is alkyl of 1 to 8 carbon atoms,alkenyl of 2 to 8 carbon atoms containing one double bond, or phenyl,and if R is alkyl or alkylene, containing 0 to 4 substituents selectedfrom the group consisting of hydroxyl, amino, and combinations thereof.

Examples of polyacids useful to form the binder material in thisembodiment thus include oxalic acid, maleic acid, succinic acid,methylsuccinic acid, malonic acid, adipic acid, glutaric acid, fumaricacid, dihydroxyfumaric acid, malic acid, mesaconic acid, itaconic acid,phthalic acid, isophthalic acid, terephthalic acid, 1,2-, 1,3- and1,4-cyclohexane dicarboxylic acid, 1,2,3-cyclohexane tricarboxylic acid,1,2,4-cyclohexane tricarboxylic acid, 1,3,5-cyclohexane tricarboxylicacid, 1,2- and 1,3-cyclopentane dicarboxylic acid, pyridine dicarboxylicacid, citric acid, tartaric acid, dihydroxyterephthalic acid, 1,2,3-,1,2,4- and 1,3,5-benzene tricarboxylic acid, tricarballylic acid,1,2,4,5-benzene tetracarboxylic acid, norbornene tetracarboxylic acid,3,3'4,4'-benzophenone tetracarboxylic acid, 1,2,3,4,5,6-benzenehexacarboxylic acid, aspartic acid, glutamic acid, and the like. Thesepolyacids may also be used in combination. Particularly preferred acidsare oxalic acid, citric acid, tartaric acid, glutaric acid, benzenetetracarboxylic acids, and benzophenone tetracarboxylic acids.

The polyacids may, if desired, be incorporated into the ink compositionin anhydride form, which will readily convert to the free acid uponadmixture with the aqueous liquid vehicle.

Similarly, the basic materials in this embodiment contain two or morebasic groups, and are preferably polyamines represented by structuralformula (II) ##STR2## wherein R, L, w, x, y and z are as defined above,and R¹ and R² are independently selected from the group consisting ofhydrogen and lower alkyl.

Examples of polybases useful to form the binder material in thisembodiment thus include the polyamines ethylenediamine,1,2-propanediamine, 1,3-propanediamine, 1,2,3-triaminopropane,cis-1,2-cyclohexanediamine, trans-1,2-cyclohexanediamine,1,3-bis(aminomethyl)cyclohexane, o-, m- and p-phenylenediamine,tetramethyl o-, m- and p-phenylenediamine, hexamethylenediamine,hexamethylenetetraamine, diethylenetriamine, tetraethylenepentamine,pentaethylenehexamine, pentamethyl diethylenetriamine,tris(2-aminoethyl)amine, 1,1,4,7,10,10-hexamethyl triethylenetetramine,tetramethyl-p-phenylenediamine, tetramethylethylenediamine,triethylenetetraamine, and mixtures thereof.

In a second embodiment, the binder matrix comprises a combination of apolymeric material having basic groups, either in the polymer backbone,as pendant moieties, or both, with an organic acid component, which maybe monomeric or polymeric. As with the embodiment discussed above, thepolymeric base and the organic acid ionically associate to form a bindermatrix which then physically entraps or ionically binds the selectedcolorant. The organic acid component may be a monoacid R³ COOH whereinR³ is equivalent to R, defined above, or it may be a polymeric orcopolymeric acid such as poly(acrylic acid), poly(acrylonitrile-acrylicacid), poly(styrene-acrylic acid), poly(butadiene-acrylonitrile acrylicacid), poly(butylacrylate-acrylic acid), poly(ethyl acrylate-acrylicacid), poly(acrylic acid-co-maleic acid), poly(ethylenepropylene-acrylicacid), poly(propylene-acrylic acid) or the like. Alternatively, theorganic acid component is a monomeric polyacid having the structuralformula (I), described in detail above.

The basic polymer in this embodiment is preferably one that has anitrogenous backbone and/or pendant amine moieties. Preferred polymersare copolymers containing first monomer units having the structure --CH₂--CH₂ --NH-- and second monomer units having the structure --CH₂ --CH₂--R⁴ -- in which R⁴ is alkyl of 3 to 8 carbon atoms, lower acyl, or--(CH₂)_(m) R⁵ wherein m is an integer in the range of 1 to 10 and R⁵ ishydroxyl, amino or --OR⁶ where R⁶ is C₁ -C₄ alkyl. The second monomerunits will generally represent in the range of approximately 20% to 95%of the copolymer, more preferably 40% to 90%, and most preferably 50% to85%; one example of such a polymer is ethoxylated polyethyleneimine,wherein the percentage of second monomer units (i.e., monomer unitshaving the structure --CH₂ CH₂ --N(CH₂ CH₂ OH)--) in the copolymerrepresents the degree of ethoxylation. These polymers may be obtainedcommercially, or they may be synthesized using conventional techniques,e.g., by treating polyethyleneimine with any one of a variety of alkylor substituted alkyl halides to provide the R⁴ substituent, in a solventsuch as methanol, dimethyl formamide, tetrahydrofuran, or the like.

Other preferred polymers are copolymers containing first monomer unitshaving the structure --CH₂ --CH₂ --NH--, second monomer units having thestructure --CH₂ --CH₂ --NR⁴ --, and additional monomer units having thestructure --CH₂ --CH(COOH)--. Such a polymer may be synthesized, forexample, by copolymerizing aziridine and a suitably substitutedaziridine with methyl acrylate, under acidic conditions. Examples ofsuch polymers and associated methods of synthesis are set forth in PCTPublication No. WO95/27759 (Nigam et al., "Water-Based Ink Compositionsand Novel Polymers Useful in Conjunction Therewith," published Oct. 19,1995).

Commercially available basic polymers which may be used include, but arenot limited to, polyethyleneimine, polyvinylpyridine, polyallylamine(including N-alkylated and N,N-dialkylated polyallylamines),polyvinylaziridine, polyimidazole, polylysine, chitosan, poly(amino andalkylated amino)ethylenes and ethoxylated polyethyleneimine.

In general, the molecular weight of any polymeric material used in thepresent ink formulations will be between about 300 and 500,000, andpreferably between about 1000 and 300,000, although smaller and largermolecular species may be used depending on the application.

In this latter embodiment, a monomeric polybase as previously describedmay be incorporated into the composition, so as to form part of thebinder matrix along with the polymeric base and the organic acidcomponent. Any of the monomeric polybases encompassed by structuralformula (II) may be used.

In either of these embodiments, the ink composition has a pH in therange of approximately 3 to 12.5, preferably in the range ofapproximately 5 to 10, and most preferably in the range of 7 to 9.5.Although the ink compositions are primarily useful for ink jet printing,they may be used in a variety of other contexts as well, as will beexplained below.

The aqueous liquid vehicle will generally be deionized water, althoughother nonorganic compounds which are either water soluble or watermiscible may be included as well. It may be necessary to add asolubilizing compound during preparation of the ink so that the bindercomponents dissolve in the aqueous liquid vehicle, e.g., an inorganicbase such as ammonia and/or an organic amine. Suitable organic aminesinclude lower alkyl-substituted amines such as methylamine,dimethylamine, ethylamine, and trimethylamine, as well as ethanolamine,diethanolamine, triethanolamine, and substituted ethanolamines,typically lower alkyl-substituted ethanolamines such as N-methyl andN,N-dimethyl ethanolamines, and morpholine. Such compounds are alsouseful for bringing the pH into the desired range for basicformulations, and, if present, will generally represent not more thanabout 20 wt. % of the composition, and in most cases will represent notmore than about 10 wt. % of the composition.

The colorant may be any pigment, dye or stain which may be dissolved,dispersed or suspended in the aqueous liquid vehicle and which iseffective to provide the dried ink with the desired color and colorintensity. The colorant is selected such that it will be immobilized bythe binder, either physically or ionically. Preferred colorants aredyes, including azo or "direct" dyes as well as dyes containing acidicgroups (e.g., carboxylate, phosphonate or sulfonate moieties), basicgroups (e.g., unsubstituted amines or amines substituted with 1 or 2alkyl, typically lower alkyl, groups), or both. In any case, thecolorant and the binder material should be selected so that incombination, the colorant becomes entrapped by the binder.

Specific examples of suitable colorants include, but are not limited to,the following: Dispersol Blue Grains (Zeneca, Inc.), Duasyn Acid Blue(Hoechst Celanese), Duasyn Direct Turquoise Blue (Hoechst Celanese),Phthalocyanine blue (C.I. 74160), Diane blue (C.I. 21180), Pro-jet Cyan1 (Zeneca, Inc.), Pro-jet Fast Cyan 2 (Zeneca, Inc.), Milori blue (aninorganic pigment equivalent to ultramarine) as cyan colorants;Dispersol Red D-B Grains (Zeneca, Inc.), Brilliant carmine 6B (C.I.15850), Pro-jet magenta 1 (Zeneca, Inc.), Pro-jet Fast magenta 2(Zeneca, Inc.), Brilliant Red F3B-SF (Hoechst Celanese), Red 3B-SF(Hoechst Celanese), Acid Rhodamine (Hoechst Celanese), Quinacridonemagenta (C.I. Pigment Red 122) and Thioindigo magenta (C.I. 73310) asmagenta colorants; Dispersol Yellow D-7G 200 Grains (Zeneca, Inc.),Brilliant yellow (Hoechst Celanese), Pro-jet yellow 1 (Zeneca, Inc.),Pro-jet Fast Yellow 2 (Zeneca, Inc.), benzidine yellow (C.I. 21090 andC.I. 21100) and Hansa Yellow (C.I. 11680) as yellow colorants; organicdyes; and black materials such as carbon black, charcoal and other formsof finely divided carbon, iron oxide, zinc oxide, titanium dioxide, andthe like. Specific and preferred black colorants include Acid Black 48(Aldrich), Direct Black 58756 A (Crompton & Knowles), BPI MolecularCatalytic Gray (Brain Power), Fasday Cool Gray (Hunter Delator),Dispersol Navy XF Grains (Zeneca, Inc.), Dispersol Black CR-N Grains(Zeneca, Inc.), Dispersol Black XF Grains (Zeneca, Inc.), Disperse Black(BASF), Color Black FW18 (Degussa), Color Black FW200 (Degussa),Hostafine Black TS (Hoechst Celanese), Hostafine Black T (HoechstCelanese), Duasyn Direct Black (Hoechst Celanese), Pro-jet Black 1(Zeneca, Inc.) and Pro-jet Fast Black 2 (Zeneca, Inc.).

Generally, it is preferred that the colorant be present in an amountranging from about 0.1 wt. % to about 20 wt. % of the ink composition,more preferably from about 1 wt. % to about 10 wt. % of the inkcomposition, and most preferably from about 1 wt. % to about 5 wt. % ofthe ink composition.

The ink compositions of the invention may contain other components aswell. It may be preferable in some cases to include a solvent having arelatively high boiling point which can serve as a humectant andsolubilizer. Suitable solvents in this regard include, but are notlimited to, triacetin, N-methyl-2-pyrrolidone, thiodiethanol, glycerol,diethylene glycol, polyethylene glycol (PEG), propylene carbonate,cyclohexanol, and 2-pyrrolidone. It may also be preferable to include ananti-foaming agent in certain compositions; examples of suitableanti-foaming agents include 1-dodecyl alcohol, Silicon Antifoam 85390(Fluka), Surfynol DF75 (Air Products), Surfynol DF210 (Air Products),Carboflow 32W (B.F. Goodrich), Tego Airex 900 (TegoChemie USA),TegoFoamex 1488 (TegoChemie USA), Siliconantifoamer S670 (Wacker) andFoam Blast 338 (Ross Chemicals). Other additives include surface tensioncontrol agents such as anionic and nonionic surface active agents,preservatives and biocides, and viscosity modifiers, as will bediscussed in further detail below. Finally, it may also be preferred insome cases to include polyethylene glycol, or alkyl or thiol derivativesthereof, when the composition is formulated for jet printing. PEG notonly serves as a humectant and solubilizer, as alluded to above, butalso lowers surface tension, improves water fastness, and reduces thelikelihood that the ink will dry on the jet printing nozzle. When PEG isincluded in the ink formulation, it should represent on the order of 0.1to 20 wt. % of the formulation, more preferably 0.1 to 10 wt. % of theformulation, and most preferably approximately 6.0 wt. %.

For jet printing inks, the binder, colorant and water will incombination generally represent at least about 65 wt. % of thecomposition, and in most cases at least about 80 wt. % of thecomposition. Also, the composition may in some cases contain monomericorganic solvents, e.g., lower alcohols or the like. Any such solventswill be present in an amount that is typically less than about 20 wt. %,of the ink composition. Certain monomeric solvents which are used inpreparation of the composition may physically or chemically interactwith the binder material so as to form part of the binder/colorantmatrix which forms the substance of the dried ink composition. Examplesof such solvents include N,N'-dimethylethanolamine, triethanolamine,diethanolamine, and the like.

The ink compositions may be prepared in any number of ways, as will beappreciated by those working in the field of printing ink chemistry andink manufacturing technology. A preferred method for formulating the inkcompositions, however, involves first dispersing the selected colorantin deionized water (or obtaining a predispersed colorant/wateradmixture), followed by admixture with a solution of the selected bindermaterial components in water. As explained above, a solubilizing agentmay be necessary to effect dissolution. This step is followed byincorporation of additives such as humectant, anti-foaming agent,surface tension control agents, and the like. This admixture is thenstirred and mixed in either a fine ball mill or an emulsifier mixer, andfiltered to achieve a particle size of less than about 5 μm, preferablyless than about 1 μm, in diameter.

The ink compositions of the invention may be used as jet printing inks,flexographic inks, lithographic inks, screen printing inks, or the like.Depending on the desired utility, the viscosity of the ink compositionwill need to be adjusted by varying the concentration of binder materialand colorant. The preferred viscosity for a composition to be used incontinuous ink jet printing is in the range of approximately 1.0 to 15cP, more preferably in the range of approximately 1.5 to 10 cP, and mostpreferably in the range of approximately 3 to 5 cP.

For "drop-on-demand" printing, e.g., in pc printers (including bubblejet and piezoelectric systems), viscosity considerations are somewhatdifferent than for other end uses, insofar as lower viscosities aregenerally preferred, typically less than about 2.5 cP, preferably lessthan about 2.0 cP, and most preferably in the range of about 1.0 to 2.0cP. Also, any components selected for use in pc printing inkcompositions should be thermally stable, as they are subjected to highertemperatures, in general, than other types of inks. Finally, pc printinginks may involve a different pH range than other types of inkcompositions, and should be substantially chloride-free to avoidcorrosive effects.

As explained in U.S. Pat. No. 5,106,417 to Hauser et al., viscosity maybe adjusted using any known substances so long as those materials do notadversely affect the ink composition and the substrate on which thecomposition is ultimately applied. Suitable viscosity control agentsinclude, for example, polyvinyl alcohol, hydroxylpropyl cellulose,methyl cellulose, water soluble acrylic resins and polyvinylpyrrolidone.

The ink compositions of the invention are not intended to be limited touse on particular substrates. The present compositions are in fact quiteversatile insofar as they may be used on paper, plastic, metal,ceramics, and the like. In some cases, for example with a number ofplastic materials, it may be necessary to pretreat the surface on whichthe ink is to be applied so that it is rendered hydrophilic, i.e., suchthat carboxyl or other ionized groups are provided thereon.

Experimental

The practice of the present invention will employ, unless otherwiseindicated, conventional techniques of synthetic organic chemistry,polymerization, ink manufacture, and the like, which are within theskill of the art. Such techniques are explained fully in the literature.See, e.g.: Kirk-Othmer, Encyclopedia of Chemical Technology (New York:John-Wiley & Sons, latest edition); House, Modern Synthetic Reactions(Menlo Park, Calif.: The Benjamin/Cummings Publishing Company, 1972);and Odian, Principles of Polymerization, Second Edition (New York: JohnWiley & Sons, 1981). All patents and publications mentioned herein areincorporated by reference.

It is to be understood that while the invention has been described inconjunction with the preferred specific embodiments thereof, thedescription above as well as the examples which follow are intended toillustrate and not limit the scope of the invention. Other aspects,advantages and modifications within the scope of the invention will beapparent to those skilled in the art to which the invention pertains.

In the following examples, efforts have been made to insure accuracywith respect to numbers used (e.g., amounts, temperature, etc.) but someexperimental error and deviation should be allowed for. Unless indicatedotherwise, temperature is in degrees Centigrade and pressure is at ornear atmospheric.

Starting materials were obtained as follows: citric acid, tartaric acid,1,2,4-benzenetricarboxylic acid, 3,3',4,4'-benzophenone tetracarboxylicdianhydride, triethylenetetramine, triethanolamine, methylamine,dimethylamine, trimethylamine, ethylamine, pentamethyldiethylenetriamine, hexamethyl triethylenetetramine, ethanolamine,3-amino-1,2-propanediol, propanolamine, diethanolamine,N,N-dimethylethanolamine, polyethyleneimine, ethoxylatedpolyethyleneimine, N-methyl-2-pyrrolidone, 2-pyrrblidone, propylenecarbonate, polyethylene glycol, diethylene glycol, thiodiethanol, fromAldrich; Carboset® polymers (e.g., Carboset® GA1594 poly(acrylic acid)),from B.F. Goodrich; Carboflow®, from B.F. Goodrich; Duasyn Direct dyes(including those designated "HEF-SF") and Hostafine dyes, from HoechstCelanese; and Projet dyes, from Zeneca.

EXAMPLE 1

A dye-based ink composition according to the invention was prepared asfollows. A mixture of 1,2,4-benzenetricarboxylic acid (8 g) and 60 mL of10% solution of triethylenetetramine were stirred together for 2 hours.Duasyn Direct black dye (2.8 g) was then added to the solution andstirring was continued until all components dissolved. Triethanolamine(10 mL) and N-methyl-2-pyrrolidone (10 mL) were also added. Theresultant composition showed very good water fastness and no bleeding byspotting on plain paper.

Analogous formulations were prepared by replacing triethanolamine withethanolamine, diethanolamine and morpholine. These also were found tohave very good water fastness after drying on plain paper, and did notdisplay any bleeding.

EXAMPLE 2

A dye-based ink composition according to the invention was prepared asfollows. Triethylenetetramine (4 g) was dissolved in 40 mL of water andDuasyn Direct black dye (4 g) was added. The contents were stirred untilthe dye dissolved. Citric acid (4 g) was dissolved separately in 20 mLof water with stirring and added to the triethylene tetramine solution.A solid separated out which dissolved upon stirring. To this solutionN-methyl pyrrolidone (5-10%) and triethanolamine (5-10%) were added andthe stirring continued. The composition showed very good water fastnessafter spotting on paper. The ink was filtered through 5.0 and 1.2 μmfilters and printed on plain paper using a Hewlett-Packard 550C Desk Jetprinter.

Analogous formulations were prepared by replacing triethanolamine withethanolamine, diethanolamine, (±)-1-amino-2,3-propanediol andmorpholine. These ink formulations were also found to have excellentwater fastness and did not bleed after spotting on plain paper.

EXAMPLE 3

A dye-based ink composition according to the invention was prepared asfollows. Tartaric acid (4 g) was dissolved in 20 mL of deionized water.In a separate beaker, triethylenetetramine (4 g) was dissolved in 40 mLof deionized water with stirring. To this was added 4 g of Duasyn Directblack dye and the stirring continued until the dye had dissolved. Thetartaric acid solution was then added and stirring was continued.N-methyl-2-pyrrolidone (5%) and triethanolamine (5%) were also added. Aswith the preceding formulation, this ink was tested by spotting on paperand then printing using an Hewlett-Packard 550C Desk Jet printer.

Analogous formulations were prepared by replacing triethanolamine byethanolamine, diethanolamine, morpholine and(±)-1-amino-2,3-propanediol. Inks so prepared displayed very good waterfastness and did not bleed after application to plain paper.

EXAMPLE 4

A dye-based ink composition according to the invention was prepared asfollows. Four g of 3,3',4,4'-benzophenone tetracarboxylic dianhydridewere placed in 30 mL of water and stirred, followed by dropwise additionof aqueous ammonia until the anhydride dissolved completely. DuasynDirect black dye (Hoechst Celanese, 5 g) was added, and the solution wasstirred. Triethylenetetramine (2 g) was dissolved separately in 10 mL ofwater. The two solutions were mixed. N-methyl-pyrrolidone (8 mL) andtriethanolamine (8 mL) were added and the contents stirred at roomtemperature. The total volume of the solution was made up to 100 mL byfurther addition of water. This was filtered through 5 and 1.2 μmfilters. This composition was tested by spotting on plain paper andprinting on plain paper using a Hewlett-Packard 550C Desk Jet printer.The ink displayed excellent water fastness and no bleeding.

This experiment was repeated by replacing ammonia with methylamine,dimethylamine, trimethylamine, ethylamine, ethanolamine,3-amino-1,2-propanediol, propanolamine and diethanolamine, giving riseto comparable water-fast ink compositions.

EXAMPLE 5

A dye-based ink composition according to the invention was prepared asfollows. A mixture of polyethyleneimine, M_(w) 750,000 (2.5 g) and1,2,4-benzenetricarboxylic acid (5 g) were mixed with 40 mL of water andstirred at room temperature. The two did not dissolve in water andformed an opaque dispersion. The dispersion was treated with ammonia andbecame a clear solution after stirring for 10-15 minutes. Duasyn Directblack dye (4 g) and N-methyl-2-pyrrolidone (5 mL) were added along withdeionized water until the total volume was approximately 80 mL. Thecontents were then stirred at room temperature. This formulationdisplayed very good water fastness by spotting on plain paper.

Analogous formulations were prepared using polyethyleneimines of varyingmolecular weights, i.e., M_(w) 700, 2,000, 5,000 and 25,000, and byreplacing ammonia with methylamine, dimethylamine, ethanolamine,diethanolamine and morpholine. All of these formulations displayed goodwater fastness after drying on plain paper.

EXAMPLE 6

A dye-based ink composition according to the invention was prepared asfollows. Polyethyleneimine, M_(w) 750,000 (4 g) was dissolved in 40 mLof deionized water and 4 g Duasyn Direct Black dye added after thepolyethyleneimine had dissolved. The mixture was stirred at roomtemperature. 3,3',4,4'-Benzophenone tetracarboxylic dianhydride (4 g)was mixed with 20 mL of water in a beaker and ammonia was added untilthe anhydride dissolved completely. The two solutions were mixed andanother 20 mL of water was added, followed by further stirring at roomtemperature. N-methyl pyrrolidone (5-10%) and ethylene glycol (2%) werealso added. After spotting on plain paper, the ink formulation displayedvery good water fastness.

Analogous formulations were prepared using polyethyleneimines of varyingmolecular weight, e.g., M_(w) 7009 2000, 5000 and 25,000, and byreplacing ammonia with methylamine, dimethylamine, ethanolamine,diethanolamine, triethanolamine and morpholine. Ink formulations wereobtained having equivalent water fastness to that described above.

EXAMPLE 7

An ink composition according to the invention was prepared by admixing1.25 g polyacrylic acid with 8.75 g deionized water, and adjusting thepH of the admixture to 10 using ammonium hydroxide. 0.32 g ofpolyethyleneimine predissolved in 12 g deionized water was added to theresin/water solution. Seven drops Hostafine Black TS pigment was thenadded and the mixture stirred. The ink was then used to write on whitepaper, allowed to dry for five minutes, and tested for fastness as inthe preceding examples. The dried ink was found to be insoluble in allof the liquids tested, including water, toluene, acetone, isopropylalcohol, and detergent solution (pH 8).

EXAMPLES 8-28

Black ink formulations were prepared using the following generalprocedure:

The indicated amount of 3,3',4,4'-benzophenone tetracarboxylic aciddianhydride was dissolved in the selected solvent (triethanolamine orN,N-dimethyl-ethanolamine) and 30 mL of water by stirring the mixture atroom temperature. The amine or imine was added, along withN-methyl-2-pyrrolidone and other components as indicated. Water wasadded to make up the volume to 100 mL. Stirring was continued at roomtemperature and the dye was added after 2 hours. The mixture wasthereafter stirred at room temperature overnight for approximately 24hours. The ink composition so prepared was then spotted on paper andtested for water fastness. The composition was then filtered through 10μm and 1 μm filter papers, loaded into a cartridge pen and test printedon different kinds of paper.

    ______________________________________                                        Ex.                                                                           ______________________________________                                        8.     3,3',4,4'-Benzophenone tetra-                                                                       =      4 g                                              carboxylic dianhydride                                                        Pentamethyl diethylenetriamine                                                                      =      2 g                                              Triethanolamine       =      10 mL                                            N-Methyl-2-pyrrolidone                                                                              =      5 mL                                             Duasyn Direct Black Dye (HEF-SF)                                                                    =      3 g                                              Total Volume with Water                                                                             =      100 mL                                    9.     3,3',4,4'-Benzophenone tetra-                                                                       =      4 g                                              carboxylic dianhydride                                                        Hexamethyl triethylenetetramine                                                                     =      2 g                                              Triethanolamine       =      10 mL                                            N-Methyl-2-pyrrolidone                                                                              =      5 mL                                             Duasyn Direct Black Dye (HEF-SF)                                                                    =      3 g                                              Total Volume with Water                                                                             =      100 mL                                    10.    3,3',4,4'-Benzophenone tetra-                                                                       =      4 g                                              carboxylic dianhydride                                                        Pentamethyl diethylenetriamine                                                                      =      2 g                                              N,N-Dimethylethanolamine                                                                            =      10 mL                                            N-Methyl-2-pyrrolidone                                                                              =      5 mL                                             Duasyn Direct Black Dye (HEF-SF)                                                                    =      3 g                                              Total Volume with Water                                                                             =      100 mL                                    11.    3,3',4,4'-Benzophenone tetra-                                                                       =      4 g                                              carboxylic dianhydride                                                        Hexamethyl triethylenetetramine                                                                     =      2 g                                              N,N-Dimethylethanolamine                                                                            =      10 mL                                            N-Methyl-2-pyrrolidone                                                                              =      5 mL                                             Duasyn Direct Black Dye (HEF-SF)                                                                    =      3 g                                              Total Volume with Water                                                                             =      100 mL                                    12.    3,3',4,4'-Benzophenone tetra-                                                                       =      4 g                                              carboxylic dianhydride                                                        Pentamethyl diethylenetriamine                                                                      =      1.8 g                                            Polyethyleneimine (MW 700 or 2000)                                                                  =      0.2 g                                            N,N-Dimethylethanolamine                                                                            =      10 mL                                            N-Methyl-2-pyrrolidone                                                                              =      5 mL                                             Duasyn Direct Black Dye (HEF-SF)                                                                    =      3 g                                              Total Volume with Water                                                                             =      100 mL                                    ______________________________________                                    

(Examples 12a-d: The formulation of Example 12 was prepared substitutingdiethylenetriamine (Example 12a), triethylenetetramine (Example 12b),tetraethylenepentamine (Example 12c) and pentaethylenehexamine (Example12d) in place of polyethyleneimine.)

    ______________________________________                                        13.    3,3',4,4'-Benzophenone tetra-                                                                       =      4 g                                              carboxylic dianhydride                                                        Hexamethyl triethylenetetramine                                                                     =      1.8 g                                            Polyethyleneimine     =      0.2 g                                            N,N-Dimethylethanolamine                                                                            =      10 mL                                            N-Methyl-2-pyrrolidone                                                                              =      10 mL                                            Polyethylene glycol   =      10 g                                             Duasyn Direct Black Dye (HEF-SF)                                                                    =      3 g                                              Total Volume with Water                                                                             =      100 mL                                    14.    3,3',4,4'-Benzophenone tetra-                                                                       =      4 g                                              carboxylic dianhydride                                                        Pentamethyl diethylenetriamine                                                                      =      1.8 g                                            Polyethyleneimine     =      0.2 g                                            N,N-Dimethylethanolamine                                                                            =      10 mL                                            N-Methyl-2-pyrrolidone                                                                              =      10 mL                                            Polyethylene glycol   =      10 g                                             Duasyn Direct Black Dye (HEF-SF)                                                                    =      3 g                                              Total Volume with Water                                                                             =      100 mL                                    ______________________________________                                    

(Examples 14a-d: The formulation of Example 14 was prepared substitutingdiethylenetriamine (Example 14a), triethylenetetramine (Example 14b),tetraethylenepentamine (Example 14c) and pentaethylenehexamine (Example14d) in place of pentamethyl diethylenetriamine.)

    ______________________________________                                        15.    3,3',4,4'-Benzophenone tetra-                                                                       =      4 g                                              carboxylic dianhydride                                                        Pentamethyl diethylenetriamine                                                                      =      2.0 g                                            N,N-Dimethylethanolamine                                                                            =      10 mL                                            N-Methyl-2-pyrrolidone                                                                              =      10 mL                                            Polyethylene glycol   =      10 g                                             Duasyn Direct Black Dye (HEF-SF)                                                                    =      3 g                                              Total Volume with Water                                                                             =      100 mL                                    16.    3,3',4,4'-Benzophenone tetra-                                                                       =      4 g                                              carboxylic dianhydride                                                        Hexamethyl triethylenetetramine                                                                     =      2.0 g                                            N,N-Dimethylethanolamine                                                                            =      10 mL                                            N-Methyl-2-pyrrolidone                                                                              =      10 mL                                            Polyethylene glycol   =      10 g                                             Duasyn Direct Black Dye (HEF-SF)                                                                    =      3 g                                              Total Volume with Water                                                                             =      100 mL                                    ______________________________________                                    

(Examples 16a-d: The formulation of Example 16 was prepared substitutingdiethylenetriamine (Example 16a), triethylenetetramine (Example 16b),tetraethylenepentamine (Example 16c) and pentaethylenehexamine (Example16d) in place of hexamethyl triethylenetetramine.)

    ______________________________________                                        17.    3,3',4,4'-Benzophenone tetra-                                                                       =      4 g                                              carboxylic dianhydride                                                        Hexamethyl triethylenetetramine                                                                     =      2.0 g                                            N,N-Dimethylethanolamine                                                                            =      10 mL                                            N-Methyl-2-pyrrolidone                                                                              =      5 mL                                             Polyethylene glycol   =      10 g                                             Diethylene glycol     =      10 g                                             Duasyn Direct Black Dye (HEF-SF)                                                                    =      3 g                                              Total Volume with Water                                                                             =      100 mL                                    18.    3,3',4,4'-Benzophenone tetra-                                                 carboxylic dianhydride                                                                              =      4 g                                              Pentamethyl diethylenetriamine                                                                      =      2.0 g                                            N,N-Dimethylethanolamine                                                                            =      10 mL                                            N-Methyl-2-pyrrolidone                                                                              =      5 mL                                             Polyethylene glycol   =      10 g                                             Diethylene glycol     =      10 g                                             Duasyn Direct Black Dye (HEF-SF)                                                                    =      3 g                                              Total Volume with Water                                                                             =      100 mL                                    ______________________________________                                    

(Examples 18a-18d: The formulation of Example 18 was preparedsubstituting diethylenetriamine (Example 18a), triethylenetetramine(Example 18b), tetraethylenepentamine (Example 18c) andpentaethylenehexamine (Example 18d) in place of pentamethyldiethylenetriamine.)

    ______________________________________                                        19.    3,3',4,4'-Benzophenone tetra-                                                                       =      4 g                                              carboxylic dianhydride                                                        Pentamethyl diethylenetriamine                                                                      =      2.0 g                                            N,N-Dimethylethanolamine                                                                            =      10 mL                                            N-Methyl-2-pyrrolidone                                                                              =      5 mL                                             Polyethylene glycol   =      10 g                                             Diethylene glycol     =      10 g                                             Propylene carbonate   =      2 g                                              Biocide               =      0.1 g                                            Duasyn Direct Black Dye (HEF-SF)                                                                    =      3 g                                              Total Volume with Water                                                                             =      100 mL                                    20.    3,3',4,4'-Benzophenone tetra-                                                                       =      4 g                                              carboxylic dianhydride                                                        Hexamethyl triethylenetetramine                                                                     =      2.0 g                                            N,N-Dimethylethanolamine                                                                            =      10 mL                                            N-Methyl-2-pyrrolidone                                                                              =      5 mL                                             Polyethylene glycol (MW 200, 400                                                                    =      10 g                                             or 600)                                                                       Diethylene glycol     =      10 g                                             Propylene carbonate   =      2 g                                              Biocide               =      0.1 g                                            Triacetin             =      1 g                                              Duasyn Direct Black Dye (HEF-SF)                                                                    =      3 g                                              Total Volume with Water                                                                             =      100 mL                                    ______________________________________                                    

(Examples 20a-20d: The formulation of Example 20 was preparedsubstituting diethylenetriamine (Example 20a), triethylenetetramine(Example 20b), tetraethylenepentamine (Example 20c) andpentaethylenehexamine (Example 20d) in place of hexamethyltriethylenetetramine.)

    ______________________________________                                        21.    3,3',4,4'-Benzophenone tetra-                                                                       =      3.8 g                                            carboxylic dianhydride                                                                              =      3.8 g                                            Pentamethyl diethylenetriamine                                                                      =      2.0 g                                            Carboset GA 1594      =      0.2 g                                            N,N-Dimethylethanolamine                                                                            =      10 mL                                            N-Methyl-2-pyrrolidone                                                                              =      5 mL                                             Duasyn Direct Black Dye (HEF-SF)                                                                    =      3 g                                              Total Volume with Water                                                                             =      100 mL                                    22.    3,3',4,4'-Benzophenone tetra-                                                                       =      3.8 g                                            carboxylic dianhydride                                                        Hexamethyl triethylenetetramine                                                                     =      2.0 g                                            Carboset GA 1594      =      0.2 g                                            N,N-Dimethylethanolamine                                                                            =      10 mL                                            N-Methyl-2-pyrrolidone                                                                              =      5 mL                                             Duasyn Direct Black Dye (HEF-SF)                                                                    =      3 g                                              Total Volume with Water                                                                             =      100 mL                                    ______________________________________                                    

(Examples 22a-d: The formulation of Example 22 was prepared substitutingdiethylenetriamine (Example 22a), triethylenetetramine (Example 22b),tetraethylenepentamine (Example 22c) and pentaethylenehexamine (Example22d) in place of hexamethyl triethylenetetramine.)

    ______________________________________                                        23.    3,3',4,4'-Benzophenone tetra-                                                                       =      4 g                                              carboxylic dianhydride                                                        Polyethyleneimine, ethoxylated                                                                      =      2 g                                              N,N-Dimethylethanolamine                                                                            =      10 mL                                            Polyethylene glycol   =      10 g                                             N-Methyl-2-pyrrolidone                                                                              =      10 mL                                            Projet Black 2        =      65 mL                                            Total Volume with Water                                                                             =      100 mL                                    24.    3,3',4,4'-Benzophenone tetra-                                                                       =      4 g                                              carboxylic dianhydride                                                        Polyethyleneimine, ethoxylated                                                                      =      2 g                                              N,N-Dimethylethanolamine                                                                            =      10 mL                                            N-Methyl-2-pyrrolidone                                                                              =      5 mL                                             Polyethylene glycol   =      10 g                                             Diethylene glycol     =      10 g                                             Projet Black 2        =      65 mL                                            Total Volume with Water                                                                             =      100 mL                                    25.    3,3',4,4'-Benzophenone tetra-                                                                       =      4 g                                              carboxylic dianhydride                                                        Polyethyleneimine, ethoxylated                                                                      =      2 g                                              N,N-Dimethylethanolamine                                                                            =      10 mL                                            N-Methyl-2-pyrrolidone                                                                              =      5 mL                                             Polyethylene glycol   =      10 g                                             Diethylene glycol     =      10 g                                             Propylene carbonate   =      2 g                                              Projet Black 2        =      65 mL                                            Total Volume with Water                                                                             =      100 mL                                    26.    3,3',4,4'-Benzophenone tetra-                                                                       =      4 g                                              carboxylic dianhydride                                                        Polyethyleneimine, ethoxylated                                                                      =      2 g                                              Ammonia               =      5 mL                                             2-Pyrrolidone         =      9 g                                              Thiodiethanol         =      9 g                                              Cyclohexanol          =      2 g                                              Projet Black 2        =      65 mL                                            Total Volume with Water                                                                             =      100 mL                                    27.    3,3',4,4'-Benzophenone tetra-                                                                       =      4 g                                              carboxylic dianhydride                                                        Polyethyleneimine, ethoxylated                                                                      =      2 g                                              Ammonia               =      5 mL                                             2-Pyrrolidone         =      9 g                                              Diethylene glycol     =      9 g                                              Cyclohexanol          =      2 g                                              Projet Black 2        =      65 mL                                            Total Volume with Water                                                                             =      100 mL                                    28.    3,3',4,4'-Benzophenone tetra-                                                                       =      4 g                                              carboxylic dianhydride                                                        Polyethyleneimine, ethoxylated                                                                      =      2 g                                              Ammonia               =      5 mL                                             N-Methyl-2-pyrrolidone                                                                              =      9 g                                              Thiodiethanol         =      9 g                                              Cyclohexanol          =      2 g                                              Projet Black 2        =      65 mL                                            Total Volume with Water                                                                             =      100 mL                                    ______________________________________                                    

All of the ink formulations prepared in these examples were found tohave very good water fastness after drying on plain paper, and did notdisplay any bleeding.

EXAMLES 29-35

Colored ink formulations were prepared using the following generalprocedure:

The carboxylic acid, ethanolamine (or substituted ethanolamine),polyethyleneimine (or ethyleneamines) were weighed in a 400 mLwide-mouthed bottle. The mixture was stirred for 30 minutes at roomtemperature or until a clear solution was obtained. Polyethylene glycol,triethanolamine and carboflow were added into the mixture (along withother additives, as indicated), and stirred for 60 minutes. Dye wasadded and the mixture stirred for approximately 24 hr. The ink wasfiltered through 5 μm and 0.65 μm millipore filters, loaded intocartridges and pens and test-printed on different types of papers.

    ______________________________________                                        Ex.                                                                           ______________________________________                                        29.      d-Tartaric Acid   =       12 g                                                Polyethyleneimine =       6 g                                                 N-Methyl-2-pyrrolidone                                                                          =       12 g                                                N,N-Dimethylethanolamine                                                                        =       21 g                                                Water             =       30 g                                                PEG (200, 400, 600)                                                                             =       30 g                                                Triethanolamine   =       6 g                                                 Carboflow 22W     =       2 g                                                 Projet Magenta-1  =       180 mL                                              Total Volume      =       200 mL                                     ______________________________________                                    

(Examples 29a-29d: The formulation of Example 29 was preparedsubstituting diethylenetriamine (Example 29a), triethylenetriamine(Example 29b), tetraethylenepentamine (Example 29c), andpentaethylenehexamine (Example 29d) for polyethyleneimine.)

    ______________________________________                                        30.      d-Tartaric Acid   =       12 g                                                Polyethyleneimine =       6 g                                                 N-Methyl-2-pyrrolidone                                                                          =       12 g                                                N,N-Dimethylethanolamine                                                                        =       21 g                                                Water             =       20 g                                                PEG (200, 400, 600)                                                                             =       20 g                                                Triethanolamine   =       6 g                                                 Carboflow 22W     =       2 g                                                 Propylene carbonate                                                                             =       6 g                                                 Projet Magenta-1  =       174 mL                                              Total Volume      =       200 mL                                     ______________________________________                                    

(Examples 30a-30d: The formulation of Example 30 was preparedsubstituting diethylenetriamine (Example 30a), triethylenetetramine(Example 30b), tetraethylenepentamine (example 30c), andpentaethylenehexamine (Example 30d) for polyethyleneimine.)

    ______________________________________                                        31.      d-Tartaric Acid   =       12 g                                                Polyethyleneimine =       6 g                                                 N-Methyl-2-pyrrolidone                                                                          =       12 g                                                N,N-Dimethylethanolamine                                                                        =       20 g                                                Water             =       20 g                                                PEG (200)         =       20 g                                                Triethanolamine   =       6 g                                                 Carboflow 22W     =       2 g                                                 Projet Cyan-1     =       171 mL                                              Total Volume      =       200 mL                                     ______________________________________                                    

(Examples 31a-31d: The formulation of Example 31 was preparedsubstituting diethylenetriamine (Example 31a), triethylenetetramine(Example 31b), tetraethylenepentamine (example 31c), andpentaethylenehexamine (Example 31d) for polyethyleneimine.)

    ______________________________________                                        32.      d-Tartaric Acid   =       12 g                                                Polyethyleneimine =       12 g                                                N-Methyl-2-pyrrolidone                                                                          =       12 g                                                N,N-Dimethylethanolamine                                                                        =       21 g                                                Water             =       20 g                                                PEG (200)         =       20 g                                                Triethanolamine   =       6 g                                                 Carboflow 22W     =       2 g                                                 Propylene carbonate                                                                             =       6 g                                                 Projet Cyan-1     =       174 mL                                              Total Volume      =       200 mL                                     ______________________________________                                    

(Examples 32a-32d: The formulation of Example 32 was preparedsubstituting diethylenetriamine (Example 32a), triethylenetetramine(Example 32b), tetraethylenepentamine (example 32c), andpentaethylenehexamine (Example 32d) for polyethyleneimine.)

    ______________________________________                                        33.      d-Tartaric Acid   =       12 g                                                Polyethyleneimine =       6 g                                                 N-Methyl-2-pyrrolidone                                                                          =       12 g                                                N,N-Dimethylethanolamine                                                                        =       21 g                                                Water             =       20 g                                                PEG (200)         =       20 g                                                Triethanolamine   =       6 g                                                 Carboflow 22W     =       2 g                                                 Projet Yellow-1   =       180 mL                                              Total Volume      =       200 mL                                     ______________________________________                                    

(Examples 33a-33d: The formulation of Example 33 was preparedsubstituting diethylenetriamine (Example 33a), triethylenetetramine(Example 33b), tetraethylenepentamine (example 33c), andpentaethylenehexamine (Example 33d) for polyethyleneimine.)

    ______________________________________                                        34.      d-Tartaric Acid   =       12 g                                                Polyethyleneimine =       6 g                                                 N-Methyl-2-pyrrolidone                                                                          =       12 g                                                N,N-Dimethylethanolamine                                                                        =       21 g                                                Water             =       20 g                                                PEG (200)         =       20 g                                                Triethanolamine   =       6 g                                                 Carboflow 22W     =       2 g                                                 Propylene carbonate                                                                             =       12 g                                                Projet Yellow-1   =       168 mL                                              Total Volume      =       200 mL                                     ______________________________________                                    

(Examples 34a-34d: The formulation of Example 34 was preparedsubstituting diethylenetriamine (Example 34a), triethylenetetramine(Example 34b), tetraethylenepentamine (example 34c), andpentaethylenehexamine (Example 34d) for polyethyleneimine.)

    ______________________________________                                        35.    d-Tartaric acid     =       4 g                                               Polyethyleneimine ethoxylated                                                                     =       2 g                                               Ammonia             =       5 mL                                              Polyethylene glycol =       8 g                                               N-Methyl-2-pyrrolidone                                                                            =       8 mL                                              Projet Magenta 2    =       64 mL                                             Total Volume with Water                                                                           =       100 mL                                     ______________________________________                                    

As with all of the ink compositions tested, each of the above coloredformulations were found to have very good water fastness after drying onplain paper, and did not display any bleeding.

Additional experiments may be conducted repeating preparation of theabove tararic acid-containing formulations, but substituting thefollowing for d-tartaric acid: 1,2,4,5-benzenetetracarboxylic acid;1,2,4-benzenetricarboxylic acid; oxalic acid; citric acid;tricarballylic acid; polyacrylic acid; glutamic acid; and α-malonicacid. The same results with respect to water-fastness are obtained.

We claim:
 1. An ink composition comprising an aqueous liquid vehicle, aneffective amount of an ionizable dye, and a binder matrix comprised of amonomeric polyacid and a monomeric polyamine ionically associatedtherewith, wherein the polyamine is selected from the group consistingof ethylenediamine, 1,2-propane diamine, 1,3-propanediamine,1,2,3-triaminopropane, cis-1,2-cyclohexanediamine,trans-1,2-cyclohexanediamine, 1,3-bis(aminomethyl)cyclohexane, o-, m-and p-phenylenediamine, tetramethyl o-,m- and p-phenylenediamine,hexamethylenediamine, hexamethylenetetraamine, diethylenetriamine,tetraethylenepentamine, pentaethylenehexamine, pentamethyldiethylenetriamine, tris(2-aminoethyl)amine, 1,1,4,7,10,10-hexamethyltriethylenetetramine, tetramethyl-p-phenylenediamine,tetramethylethylenediamine, and triethylenetetraamine, and combinationsthereof.
 2. An ink composition comprising an aqueous liquid vehicle, aneffective amount of a colorant, and a binder matrix comprising amonomeric polyacid having the structure of formula (I) and a monomericpolybase having the structure of formula (II) ##STR3## wherein: R isselected from the group consisting of alkyl, alkenyl, aryl of 1 to 3rings which may be fused or linked, and 5- and 6-membered heterocyclicrings having from 1 to 3 heteroatoms selected from N, S and O;R¹ and R²are independently selected from the group consisting of hydrogen andlower alkyl; L is an alkylene or alkenylene chain containing 1 to 8carbon atoms; w is 0 or 1; x is 0 or 1; y is an integer in the range of2 to 10 inclusive; and z is 1, 2 or 3, with the provisos that (a) if wis 0 and x is 0, then y is 2 and z is 2, and (b) if z is 2 or 3, thedistinct R groups are covalently linked to each other.
 3. The inkcomposition of claim 2, wherein:w is 1; x is 0; y is an integer in therange of 2 to 6 inclusive; z is 1; and R is alkyl of 1 to 12 carbonatoms substituted with 0 to 4 substituents, alkenyl of 2 to 12 carbonatoms substituted with 0 to 4 substituents and containing 1 or 2 doublebonds, or aryl of 1 to 2 rings substituted with 0 to 4 substituents andeither fused or linked.
 4. The ink composition of claim 3, wherein:w is1; x is 0; y is 2, 3 or 4; z is 1; and R is alkyl of 1 to 8 carbon atomssubstituted with 0 to 4 substituents, alkenyl of 2 to 8 carbon atomssubstituted with 0 to 4 substituents and containing 1 double bond, orphenyl, wherein the substituents are selected from the group consistingof amino, hydroxyl, and combinations thereof.
 5. The ink composition ofclaim 1, wherein the monomeric polybase is a polyamine selected from thegroup consisting of ethylenediamine, 1,2-propane diamine,1,3-propanediamine, 1,2,3-triaminopropane, cis-1,2-cyclohexanediamine,trans-1,2-cyclohexanediamine, 1,2-bis(aminomethyl)cyclohexane, o-, m-and p-phenylenediamine, tetramethyl o-, m- and p-phenylenediamine,hexamethylenediamine, hexamethylenetetraamine, diethylenetriamine,tetraethylenepentamine, pentaethylenehexamine, pentamethyldiethylenetriamine, tris(2-aminoethyl)amine, 1,1,4,7,10,10-hexamethyltriethylenetetramine, tetramethyl-p-phenylenediamine,tetramethylethylenediamine, triethylenetetraamine, and combinationsthereof.
 6. The ink composition of any one of claims 1, 2 or 5, furtherincluding a humectant.
 7. The ink composition of any one of claims 1, 2or 5, further including polyethylene glycol.
 8. The ink composition ofany one of claims 1, 2 or 5, further including a viscosity modifier. 9.The ink composition of any one of claims 1, 2 or 5, further including asurface tension control agent.
 10. The ink composition of any one ofclaims 1, 2 or 5, further including a solubilizing compound effective toprovide a solution of the first and second components in the aqueousliquid vehicle.
 11. A binder material comprised of a monomeric polyacid,a monomeric polybase ionically associated therewith to form a matrix,and an ionizable dye entrapped within the matrix, wherein the monomericpolyacid has the structure of formula (I) and the monomeric polybase hasthe structure of formula (II) ##STR4## wherein: R is selected from thegroup consisting of alkyl, alkenyl, aryl of 1 to 3 rings which may befused or linked, and 5- and 6-membered heterocyclic rings having from 1to 3 heteroatoms selected from N, S and O;R¹ and R² are independentlyselected from the group consisting of hydrogen and lower alkyl; L is analkylene or alkenylene chain containing 1 to 8 carbon atoms; w is 0 or1; x is 0 or 1; y is an integer in the range of 2 to 10 inclusive; and zis 1, 2 or 3, with the provisos that (a) if w is 0 and x is 0, then y is2 and z is 2, and (b) if z is 2 or 3, the distinct R groups arecovalently linked to each other.
 12. The binder material of claim 11,wherein:w is 1; x is 0; y is an integer in the range of 2 to 6inclusive; z is 1; and R is alkyl of 1 to 12 carbon atom substitutedwith 0 to 4 substituents, alkenyl of 2 to 12 carbon atoms substitutedwith 0 to 4 substituents and containing 1 or 2 double bonds, or aryl of1 to 2 rings substituted with 0 to 4 substituents and either fused orlinked.
 13. The binder material of claim 12, wherein:w is 1; x is 0; yis 2, 3 or 4; z is 1; and R is alkyl of 1 to 8 carbon atoms substitutedwith 0 to 4 substituents, alkenyl of 2 to 8 carbon atoms substitutedwith 0 to 4 substituents and containing 1 double bond, or phenyl,wherein the substituents are selected from the group consisting ofamino, hydroxyl, and combinations thereof.